This application claims the benefit of U.S. Provisional Application Ser. No. 60/937,903 filed on Jun. 29, 2007. The present invention concerns novel 4-chloro-4-alkoxy-1,1,1-trifluoro-2-butanones, a process for their preparation and a process for using them to prepare 4-alkoxy-1,1,1-trifluoro-3-buten-2-ones.
4-Alkoxy-1,1,1-trifluoro-3-buten-2-ones are useful intermediates for preparing pesticides; see, for example, U.S. Patent Publication 2005/0288511. Their preparation has previously been described, for example, in U.S. Pat. Nos. 5,708,175; 7,057,079 B2; WO 2004/108647 A2; and U.S. Patent Application Publication 2006/0084813 A1. Unfortunately, 4-alkoxy-1,1,1-trifluoro-3-buten-2-ones are relatively expensive and somewhat unstable, i.e., it is recommended that they be stored under refrigeration. It would be desirable to have a less expensive process to prepare 4-alkoxy-1,1,1-trifluoro-3-buten-2-ones. It would also be desirable to have a more stable precursor which could be more easily transported and stored or, alternatively, could be easily generated in situ.